Railway traffic controlling system



Sept. 22, 1931. s. N. WIGHT 1,324,135

RAILROAD TRAFFIC CONTROLLING SYSTEM Original Filed May 16, 1927 -'.'De-ener9i5ed a position 24 INVENTOR BY 6: i. w

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Patented Sept. 22, 1931 UNITED STATES PATENT orFIcE SEDG-WICK N. WIGHT, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, OF ROCHESTER, NEW YORK RAILWAY TRAFFIC CONTROLLING SYSTEM Original application filed May 16, 1927, Serial N0. 191,735. Patent No. 1,792,455, dated February 10, 1931.

Divided and. this application filed January 2, 1931. Serial No. 506,031.

This invention relates to signaling systems for single track railroads, and more particularly to apparatus and circuits for controlling the directional stick relay in an absolutepermissive-block signal system which uses color light signals.

In an absolutepermissive-block signal system, such as shown and described, for example, in my prior Patent No. 1,291,? February 18, 1919, there is employed a d1- rectional stick relay for each intermediate signal, which is energized by train movements by that signal in the direction of traffic governed thereby, but which is not energized for an opposing train movement. The control of this directional stick relay involves a signal or line relay governed by two adjacent track circuits in advance of the signal.

Since the ordinary track relay commonly used is usually quicker in picking up than in dropping, an engine and tender alone, or a motor car, travelling at a speed from one track section to another, may allow the first track relay in the rear to pick up, before the next track relay in advance drops, thereby momentarily energizing the line relay controlled by these two track relays. Such momentary energization of the line relay may, under certain conditions and with certain types of control of the directional stick relay, cause an improper energization of the directional stick relay by an opposing train movement.

In accordance with the present invention, it is proposed to provide special slow acting circuit controlling means, governed by the line relay, for controlling the pick up circuit of the directional stick relay so constructed as to prevent such improper energization of the directional stick relay.

This application is a division of my prior application, Ser. No. 191,735, filed May 16, 1927, which matured into Patent No. 1,792,- 455, dated February 10, 1931.

In the accompanying drawings, Fig. 1 illustrates in a simplified and diagrammatic manner the invention applied to one intermediate signal; and Fig. 2 is a fragmentary view of the slow-acting mercury contactor forming a part of the invention.

In order to simplify the explanation of the present invention, only the control circuits and apparatus for the intermediate signal 3 are shown. This signal 3 is a color light signal of any suitable type, and is assumed to be one having three lamps G, Y, and R, which when lighted respectively give a green or proceed indication, a yellow or caution indication, and a red or stop indication. The marker light M being staggered with respect to the indicating lamps of the signal 3 identify this signal as a permissive signal.

The portion of signal track between the signals 1 and 3 is divided into the usual way into two track circuit sections, each provided with a track battery B and a suitable track relay. The track relays for these sections have been shown conventionally by dotted lines designated QT and 3T.

Associated with thesignal 3, is a home or line relay 3H, a slow-releasing polechanger relay 31 C, and a directional stick relay 38. The line relay 3H is directly controlled by the track relays QT and ST by an energizing circuit traced from Bi, through the front contact 11 of track relay 2T, wire 12, front contact 13 of track relay 3T, wire 1%, relay 3H, to C. This relay SE is energized with current of one polarity when the signal 1 next in advance, governing trafiic in the same direction, indicates clear or caution, and with the opposite polarity when the signal indicates stop, in accordance with well-known practice.

The relay 31 C is directly controlled by the relay 3H over a local circuit from (-1-), front contact 15 of relay 3H, wire 16, relay 3PC, to

The home or line relay 3H is a neutralpolar relay of the usual construction; and

its polar contacts, in conjunction with front and back contacts of the relay 3PC, control the lighting of the lamps G, Y, and R of the signal 3 in the usual way, the circuits for these lamps being shown by dotted lines.

The relay 3P0 is preferably provided with copper slugs, or equivalent means Well the dotted line position.

known in the art, so as to be slow-releasing. Also, it is provided with a special slow-acting mercury contactor, designated as MC, and shown more in detail in Fig. 2. In the particular construction shown, this mercury contactor MC comprises a hermetically sealed glass tube 49, pivotally supported at 50, and suitably connected, as diagrammatically indicated in Fig. l, to the movable armature or the contact finger .2 of the relay 3P6, this tube 49 being tilted to the position shown in Figs. 1 and 3, when the armature of the relay 3P6 is in its attracted position. The glass tube l9 is partly filled with mercury and an inert gas, and contains a check valve 51, with a restricted orifice 52 therein, which permits free flow of mercury from one end of the tube to another, but retards the flow of mercury in the-other direction. Wires or electrodes 2%: and an, sealed in this glass tube in the usual way, are connected to wires 23 and 25; and when these electrodes are connected by the mercury, as shown in Fig. 2, the circuit including the said wires is completed.

Assume a train traveling from right to left in the direction of trafiic governed by the signal 3. When this train passes the signal 3 and drops the track relay 3T, the back contact 22 of this track relay is closed at the same time as its front contact H 13 opens to break the energizing circuit for the line relay 3H. The de energization of the line relay 3H opens its front contact 15 and breaks the'energizing circuit for the relay 3PC. \Vhen the relay 31 C is de-energized, the glass tube a9 is tilted from the position shown by full lines in Fig. 2 to The check valve 51 permits the mercury in the tube 49 to flow relatively quickly to the other end of the tube and break the electrical connection between the Wires or electrodes 242 l As soon as the back contact 22 of the track relay 3T closes, and before there is time for the relays and 3PC to become de energiz'ed and the electrical connection between the electrodes 2 l2l to become broken, due to the slow-releasing characteristics of the relay 3? and the delay in the movement of the mercury in the glass tube l9, the directional stick relay 3S is picked up overa circuit from back contact 22 of track relay 3T, wire 23, mercury contacts 2 l2 l, wires 25, 2G, and 27, relay 3S to The relay 3S is stu'ck'up through a circuit from front contact 30 of relay 3S, wires 31 and 32, back contact 3?) of relay 3H, wires and 27, relay 38, to lVhenthe relay 3 l closes its back contact 35, another stick circuit for the relay 3i is completed from front contact 30 of reb ck contacts 33 and 35 to break the stick circuits for the relay 3S, whereupon this relay assumes its normal de-energized condition.

The directional stick relay 38, when energized, provides a shunt for the front contact 20 of the relay 3PC controlling the line circuit 21 extending to the signal (not shown) next in the rear of the signal 3 and governing trahic in the same direction, so that this signal in the rear may clear for a following train movement, in the wellknown manner characteristic of an absolutepermissive-block signal system, and as explained more in detail in my prior patent above mentioned.

The directional stick relay 3S associated with the si nal 3 is not energized by an eastbound train traveling in a direction opposite to the direction of traflic governed by the signal 3. In other words, the relay 3S is not energized 'for'an opposing train movement. This is because an eastbound train, approaching the signal 3, when it drops the track relay 2T, causes deenergization of the relays 3H and 3PC, and the resultant opening of the contacts 2l24, before this train reaches the next track circuit and drops the track relay 3T.

Considering 'now the conditions which this invention is particularly devised 'to satisfy, assume an engine and tender alone, or a motor car, traveling from left to right toward the signal When this vehicle enters the first track circuit anddr ops the track relay 2T, the relays 3H and 3PC are de-energized in the usual way. Vfhen this vehicle passes from the first track circuit into the next, it may happen that the track relay 2T will pick up before the track "relay 3T drops, thereby momentarily energizing the relay 3 l and in turn the relay 3P0. uen the track relay 3T drops, the relays 1 and 3PC are again de-energized; but at the time :the track relay 31 drops and closes its back contact 22, the relay 3P0 may have its armature in the attracted position. Under these conditions, if the pickup circuit for the'relay 38 should include a front contact of the usual construction operated by the relay 3P8, the stick relay 3S might be improperly picked up and stuck up the same as 'for a wcst bound train movement. Such improper energization of the relay 3S, if it occurred, would permit the opposing signal in the rear of the signal 8 to clear, when it should be held at stop by the east-bound engine or motor car under consideration; and under certain conditions of movement of opposing trains, adequate and safe signaling protection would not be afforded.

Such improper energization of the directional stick relay 3S, as just described, is positively prevented according to this invention by the slow-acting characteristics of the mercury contactor MC actuated by the the relay 3P0. After this relay 31 6 has once been de-energized for some time, as would be true in the case of an eastbound engine under consideration, the glass tube 49 is in the dotted line position shown in Fig. 2, and the mercury is all in the end of the tube opposite the electrodes 24-24. hen the relay 31 C is again energized, the glass tube 49 is tilted to the position int icated by full lines in Fig. 2; but the movement of mercury to the other end of the tube is retarded by the check valve 51 and restricted orifice 52, so that the pick-up circuit for therelay 38 through the electrodes 24.-24 is not established for a time interval. This interval of delay is determined by the size of the orifice 52 and volume of the mercury; and the parts are so constructed and arranged that the pick-up circuit for the relay 3S is maintained opened at the contacts 2-il24l long enough for the relay 3H to be again de-energized by the dropping of the track relay 3T, and the relay 3PC in turn de-energized to tilt the tube 49 to the other or de-energized position shown in dotted lines in Fig. 2. In this way, the improper energization of the directional stick relay 38 cannot occur under the conditions above explained.

The time delay in closing the pick-up circuit for the relay 3S through the contacts 2a 2a after this pick-up circuit has been broken for some time, does not interfere with the normal and regular operation, since the relay 3PG is energized at the time a west-bound train will pass the signal 3.

Although the mercury contactor MC may be made relatively slow in opening the contacts 24-2? upon de-energization of the relay 3P0, suflicient to provide for the normal picking-up operation of the relay 3S, the relay 3P6 is preferably made inherently slow-releasing, in order to avoid the giving of a momentary red or stop indlcation during the reversal of the polarity of energization of the relay 3H, to change from a caution to a clear indication, due to the fact that the neutral armature of the relay 3H drops momentarily during such reversal. If it were not for this condition, the relay 31 C could be made so that its armature would respond quickly to energization or deenergization of this relay; and the necessary time delay in opening and closing-the pickup circuit of the relay 3S could be obtained by the operation of the mercury contactor MC; but as above explained, this mercury contactor is preferably constructed so as to be slower in closing the contacts 242l than opening them. In this connection, it should be understood that the use of copper slugs or the like to make the relay SPC slow releasing, with the constructions ordinarily employed, does not make this relay equally slow in picking up, and also that it is desirable in many cases to make the time delay inclosing the contacts 2 l24 in the pick-up circuit for the relay 3S somewhat greater than the time delay in opening these contacts.

The specific embodiment of the invention shown and described is susceptible of various modifications and adaptations, without departing from the invention.

What I clam is 1. In a signaling system of the type described, a line relay controlled by two adjacent track circuits, a repeater relay controlled by said line relay, said repeater relay having contacts directly actuated by its armature which are slow in closing upon movement of said armature to its attracted position, and a directional stick relay having a pick-up circuit including said contacts.

2. A signaling system of the type described, a line relay controlled by two adjacent track circuits, and a repeater relay controlled by said line relay, a time responsive contactor actuated by the movement of the armature of said repeater relay and having contacts slow to close upon energization of said repeater relay, and a directional stick relay controlled by said contacts and by one of said track circuits.

3. A system of the type described, a repeater relay governed by two adjacent track circuits and having normally open and normally closed contacts respectively closed and opened successively after an interval of delay following de-energization of said relay, a directional stick relay, a pick-up circuit for said stick relay including said normally closed contacts, and a stick circuit for said stick relay including said normally open contacts.

4. In a system of the type described, the combination with a directional stick relay, a repeater relay governed by two adjacent track circuits, a slow-acting contactor device actuated by the movement of the armature of said repeater relay and having contacts in the pickup circuit for said stick relay which remain open for a limited time interval each time said repeater relay is energized after being de-energized.

5. In a system of the type described, the combination with a directional stick relay, a slow-acting relay having contacts controlling the-energization of said stick relay, said contacts being normally closed and opening relatively quickly upon de-energization of said relay, said contacts also closing relatively slowly upon re-energization of said relay, and other contacts operated by said slow-acting relay for controlling the stick circuit of said stick relay.

6. In a signaling system of the type described, a line relay controlled by two adjacent -track circuits, a repeater relay having normally closed contacts closed after an interval-of delay upon attraction-of its armature and back contacts closed relatively quickly upon retraction of its armature, a directional stick relay, a pick-up circuit including said normally closed contacts and controlled by oneo'f said track circuits, and a stick circuit for said stick relay including said back contacts.

7. In a system of the type described, a color light signal, a line relay controlled by two adjacent track circuits, a slow-releasing relay governed by said line relay, control circuits for said light signal governed by saidline relay and said slow-releasing relay, a directional stick relay having a pickup circuit, and a contacting device directly operated by movement of the armature of said slow-releasing relay and included in said pick-up circuit, said contacting device including means retarding the closing of its contacts -for a time interval following attraction-of the armature-of said slow-releasing relay.

In testimony whereofl affiX my signature.

SEDGWICK N. lVIGI-IT. 

